Can type, click, watch game play on while nothing works.

I can play league fine one day and others I will just lose total control over my character. I can type, click and move mouse, hit buttons and see the hotkeys light up but nothing I input actually works. My character just stays in the last spot that I clicked. There is no lag, the game continues on like normal and I can watch everyone play, type and ask why I'm not moving but I can not do anything in response. Please help thanks.